*Updated: 27 June 2009 Saturday.*

Final Course Grades and Breakdown by Category 6/27/2009 Saturday

Monday 6/22: THE LAST LECTURE. "A Taste of Modern Physics" -- goes
to size/time/length scales far outside our normal experience. The point of
today's lecture is to give you a taste for how strange things get in the real
world. **Relativity**. Classical Relativity (two observers, two frames of
reference), Special Relativity (speed constant), General Relativity
(accelerations or gravity). Einstein's postulates: (1) All observers see the
same Physics laws. (2) All observers measure the speed of light in vacuum as c.
Beta, gamma, Length Contraction and
Time Dilation. No preferred observer in Special Relativity. Two observers
cannot agree on what they see, distance or time. One sees the proper length: a
length measurement where both ends are measured at the same time. One sees the
proper time: a time measurement where beginning and end are measured at the
same place. Experimental confirmation of Special Relativity: put atomic clocks
on aircraft, spacecraft. Difference in time with identical clocks left on the
ground. Two observers cannot agree on the *order* of events, either. The
concept of "simultaneity" is gone. **Quantum Mechanics**. *...
the Bohr Atom (derivation on the reverse side Dr. Phil's Periodic Table) to see
how Coulomb's Law combines with Uniform Circular Motion and the Modern Physics
concepts of the deBroglie wavelength (matter also has wave-particle duality)
and quantum physics (like the stepped terraces of our lecture hall, 1110 Rood,
the electron cannot exist at just any energy level or radius from the nucleus).
In effect, the allowed electron orbitals in the Bohr Atom are standing waves
set on a circular string. (ooh!) The deBroglie wavelength -- Wave/Particle
Duality for Matter. Planck's constant -- a very small number, but it is NOT
zero ( h = 0 in Classical Physics). So the deBroglie wavelength only matters
for very small objects, not Buicks. For an electron to move from one orbit to
another, it must gain or lose energy. Going from a higher n to a lower n, the
difference in the energy is release as a photon with E = hf. To go from a lower
n to a higher n, the electron has to absorb a photon of E=hf. And now we have
an explanation of the spectral lines which we had once described as
"fingerprints for elements". Burn hydrogen and the light emitted,
when run through a prism will split not into a rainbow, but individual lines of
individual colors -- these are emission lines. Take white sunlight, shine it
through a prism and look at the rainbow of colors under a microscope and you
will see that individual lines of color are missing -- these are absoption
lines caused by the hydrogen gas in the Sun's atmosphere removing those colors
and moving their electrons to higher orbits or ionizing completely.* *If
we try to solve the helium atom (Z=2) in a similar way, we find that with one
nucleus and two electrons, we have a three-body problem and we can't solve that
in closed form. However, we can use our Bohr equations for hydrogenic ions
(hydrogen-like) which have only one electron, so we can solve for
He ^{+}, Li^{+2}, Be^{+3}, B^{+4},
C^{+5}, ... , U^{+91}, etc.* Handouts: Dr. Phil's
Periodic Table and From UCM to Spectral
Photons.

Q23 (The Last Quiz) is used as a Check-Out Form at the Final Exam (Tuesday 26 June 2007, 2:00-4:00pm, Be There!), so the points are really a "freebie". That means no more quizzes for the semester. You're welcome.

Due to time constraints, we obviously have not covered all the material in the text. If you want a rough guide to the topics we didn't cover at the end of the textbook, check out these topics from the PHYS-1150 course.

Tuesday 6/23: FINAL EXAM from 2pm to 4pm (2 Full Hours).

Wednesday 6/24: Not on campus today.

Thursday 6/25: ~~Dr. Phil may or may not have
office hours today~~. Not on campus
today.

Friday 6/26: Office Hours.

Monday 6/29: Office Hours.

Tuesday 6/30: Grades due by NOON to Registrar. Do NOT call me in the morning. Dr. Phil will not be in today. Office Hours webpage will be updated for Grading Week and Beyond.

Monday 5/4: Class begins. The nature of studying Physics. Science education in the United States. Natural Philosophy. The Circle of Physics. Aristotle and the Greek Philosophers. Observation vs. Experiment - Dropping the book and the piece of paper (2 views). Mechanics is the study of motion. So what is motion? Zeno of Elea -- Zeno's Paradoxes. First Equation: Speed = Distance / Time.

Tuesday 5/5: "Speed Limit 70" First Equation: Speed = Distance /
Time. v = d/t . Development of Speed equation for Constant or Average Speed.
delta-x = x_{f} - x_{i} , x = x_{0} + v t . Distribute
syllabus. Topic 1 assigned. (Searchable
booklist available online here --or-- the entire
handout in .pdf format here.)

Wednesday 5/6: No class.

Thursday 5/7: English system of measurement. SI Metric System.
Prefixes. What do we mean by Measurements?
"Units will save your life." What is "1 m/s"? We need a few
benchmark values to compare English and SI Metric quantities. *NOTE:
English-to-Metric conversions will NOT, with two exceptions, be tested on in
this course. *60 m.p.h. = 26.8 m/s. 1.00 m/s = slow walking speed. 10.0 m/s
= World Class sprint speed (World Record in 100m dash -- 9.69 seconds -- set at
Beijing 2008 Summer Olympics). 343 m/s = Mach 1 (speed of sound). 8000 m/s =
Low Earth Orbital Speed. 11,300 m/s = Earth escape velocity. 300,000,000 m/s =
Speed of light. PTPBIP - Putting The Physics Back Into The Problem. A
simplified trip to the store -- The S-Shaped
Curve. Acceleration. Finding the set of
Kinematic Equations for constant acceleration. Kinematic Equations for Constant Acceleration.
The Equation Without Time -- Avoiding the Quadradic Formula. Finishing
The S-Shaped Curve: plotting x-vs-t gives
straight line in Region II, but parabolic curves for Regions I and III.
Problem: A rifle bullet is fired from rest to nearly twice the speed of sound,
444 m/s, in a distance of 1.00 m. Find *a*. Answer, *a = 98,570
m/s²*. This is huge, which is why we don't fire people out of rifle
barrels. Find *t = 0.004504sec*. Again, we can solve for *t* using
two different equations, but will still get the same result because there is
one Physics. To aid in setting up problems with the kinematic equations, you
might try to list all six kinematic variables (x_{0}, x, v_{0},
v, a and t) and give the values for those you know, those you don't know and
those you want to find out. This will help you choose which kinematic
equation(s) you'll need. Q1 and your PID number. (If you missed class on this
day, check with Dr. Phil sometime soon.)

Friday 5/8: 9/9: Speed. 60 m.p.h. = "A Mile A Minute". It's a nice
alliterative phrase and wasn't possible for Man to move at 60 mph until 1848:
The Antelope, but
it really isn't a special speed, just an accident of the English system of
measurement. What do we mean by a = 1 meter/sec² ? You cannot accelerate
at 1 m/s² for very long. Finishing The
S-Shaped Curve: Physics Misconceptions: Things you
think you know, are sure you know, or just assume to be true in the back of
your mind... but aren't true. Aristotle was sure that heavier objects always
fell faster than lighter objects, but we did a demostration on Wednesday which
showed that wasn't always true. Example: You're driving a car. To speed up, you
need to put your foot on the accelerator (gas pedal), so YES, you are
accelerating -- True. To drive at a constant speed, you must still have your
foot on the accelerator, so YES, you are accelerating -- Not True because
constant v means a = 0. To slow down, you must take your foot off the
accelerator and put it on the brake pedal, so NO, you are not accelerating --
Not True because v is changing, so a < 0 (negative). Look at real
world v-vs-t graphs in a car magazine (*Road & Track*, *Car &
Driver*, *Motor Trend*) this weekend! Problem: A car starts at rest,
then accelerates to a speed of 26.8 m/s (60 mph) in 12.0 sec. (a) Find
acceleration *a*. (b) Find distance traveled *x*. Assume
*x _{0} = 0*. Use 1st kinematic equation to find (b) -- and check
the solution with 4th kinematic equation, The Equation Without Time. Dr. Phil's
Reasonable Significant Figures. Handout on (1) Prefixes for moving the decimal
place for larger and smaller powers of ten in the SI metric system, (2)
Scientific Notation, as in 1.23 × 10

Monday 5/11: The P-O-R (Press-On-Regardless) road rally problem. "You
can't average averages." Comments on Q2 -- solution already posted on
class webpage. Free-Fall: If we ignore air resistance, all objects near the
surface of the Earth fall towards the Earth at the same rate. *a _{y}
= -g* ;

Tuesday 5/12: Two kinds of numbers: Scalars (magnitude and units) and
Vectors (magnitude, units and direction). Adding and subtracting vectors:
Graphical method. To generate an
analytical method, we first need to look at some Trigonometry.
Right Triangles: Sum of the interior angles of
any triangle is 180°, Pythagorean Theorem (a² + b² = c²).
Standard Angle (start at positive *x*-axis and go counterclockwise).
Standard Form: 5.00m @ 30°. Practical Trigonometry.
S`OH`C`AH`T`OA`. Adding and subtracting vectors:
Analytical method. (Check to make
sure your calculator is set for Degrees mode. Try cos 45° = sin 45° =
0.7071) Why arctangent is a stupid function on your calculator. *For
studying, find vector D = vector A - vector B, where in class you were given
vector A = 5.00 m @ 30° and vector B = 7.00 m @ 120°* . Q5
Take-Home, due Friday 15 May 2009 in class or by 5pm.

Wednesday 5/13: No class.

Thursday 5/14: Finding the final vector velocity of The guy with the fedora
and the cigar problem. Two Dangerous
Equations. You can only use the Range Equation if the Launch Height =
Landing Height. But the sin (2*theta) term in the Range Equation means that (1)
45° gives the maximum range for a given initial velocity and (2) that all
other angles have a complementary angle (90° - theta) that gives the same
range (but a different time and height). High and low trajectories for Range
Equation. Types of Motion studied so far: No motion, Uniform motion
(v=constant, a=0), Constant Acceleration. Uniform Circular Motion (UCM): speed
is constant, but vector velocity is not; magnitude of the acceleration is
constant, but the vector acceleration is not. Velocity is tangent to circle,
Centripetal Acceleration is perpendicular to velocity and points radial INWARD.
a_{c} = v²/r. Space Shuttle in Low-Earth Orbit. (There's still
gravity up there!) Second set of Sample Exam 1's handed out. (Click
here and here
for a copy.) Q6 Take-Home, due Monday 18 May 2009 in class or by 5pm.

Friday 5/15: [UPDATED POSTING] Demo: Rodney Reindeer and U.C.M. The guard
around a circular saw blade takes the sawdust and broken bits which shoot out
tangentially from the blade and redirects them to a bucket -- improves safety
and makes less of a mess. UCM can generate some very large accelerations. How
large? Comparison to Free-Fall: If we ignore air resistance, all objects near
the surface of the Earth fall towards the Earth at the same rate.
*a _{y} = -g* ;

Monday 5/18: Demo: Toss a piece of chalk horizontally and drop a second
piece -- they both hit the table at the same time, because they have the same
*y*-problem of free-fall in the vertical. Cannot aim directly at an
object, have to allow for the drop. That's why the arrow in Q6 is launched at
an angle in order to reach the target at the launch height. Dr. Phil's Second
request for questions on Sample Exam 1's -- second time, no questions. Newton's
Three Laws of Motion: Zeroeth Law - There is such a thing as mass. First Law -
An object in motion tends to stay in motion, or an object at rest tends to stay
at rest, unless acted upon by a __net external force__. Second Law - F=ma.
Third Law - For every action, there is an equal and opposite reaction,
__acting on the other body__. (Forces come in pairs, not apples.) SI unit of
mass = kilogram (kg). SI unit of force = Newton (N). English unit of force =
pound (lb.). English unit of mass = slug (Divide pounds by 32. For English
units, g = 32 ft/sec².). Force is a vector. Q7 in-class quiz on UCM.

Tuesday 5/19: Exam 1.

Wednesday 5/20: No class.

Thursday 5/21: Return X1. Newton's 3 Laws continued. Force is a vector. Free
Body Diagrams. Normal Force (Normal = Perpendicular to plane of contact). The
normal force does NOT automatically point up and it is not automatically equal
to the weight -- we have to solve for the normal force. "The Normal Force
is NOT automatically present -- you have to be in contact with a surface. The
Normal Force does NOT automatically point up -- F_{N} is perpendicular
to the surface. The Normal Force is NOT automatically equal to the weight.
F_{N} = mg only if there are no other forces in the y-direction."
Sum of forces in *x* or *y* equations -- either will be equal to 0
(Newton's 1st Law) or *ma* (Newton's 2nd Law). Example of 125 kg crate
being dragged/pushed around. (Near the surface of the Earth, you can use the
relationship that 1 kg of mass corresponds [not "equals"] to 2.2 lbs.
of weight. So multiple 125 by 2 and add 10%... 250 + 25 = 275... so a 125 kg
crate has a weight of mg = 1226 N or 275 lbs.). Variations as we allow for an
applied force that it at an angle. Push down and Normal Force increases; pull
up and Normal Force decreases -- though it cannot go negative. "You can't push on a rope." Since the
force from a wire/string/rope/chain/thread/etc. can only be in one direction,
Dr. Phil prefers to call such forces T for Tensions rather than F for Forces.
Simple pulleys (Massless, frictionless, dimensionless, only redirect the
forces). "There is no free lunch." The bracket for the pulley will
have to support a force greater than the weight of the hanging object.
Mechanical advantage: multiple pulleys allow us to distribute the net force
across multiple cables or the same cable loop around multiple times. Tension in
the cable is reduced, but you have to pull more cable to move the crate. Q8
Take-Home, due Friday 22 May 2009.

NOTE: If you are keeping score, you'll realize that we are in Chapter 2 of your textbook. Though I continue to do some things different from the text, you should read through Chapter 1 and the parts of Chapter 2 we've already covered. My intent is to use the textbooks as "a second voice" -- a different way of explaining things than I give you in class. This can be very useful to either (a) see a different way of looking at the class material or (b) suddenly say to yourself, "Hey, I understand what that means!" From now on, the textbook will be increasingly more useful.

Friday 5/22: *YES! We have class on Friday. There is not an early start to
the Memorial Day Weekend. We do get Monday 25 May 2009 off as a holiday.*
Hanging a sign with angled wires -- still the same procedure: Sketch of the
problem, Free Body Diagram, Sum of Forces equations in the x- and y-directions,
solve for unknowns. *For the problem in class, we had a sign with m = 15.0 kg
and two tension forces, T _{1}-vector = 107.7 N @ 150° and
T_{2}-vector = 131.9 N @ 45°. You can check to make sure these
forces cancel in the x-direction and support the weight of the sign in the
y-direction. *Elevator Problems. The Normal Force represents the
"apparent weight" of the person in the elevator. For the elevator at
rest or moving at constant speed, the Normal Force = weight, and the tension of
the cable = weight of loaded elevator. But if there is an acceleration vector
pointing up, the apparent weight and the tension of the cable increase; if the
vector points down, the apparent weight and the cable tension decrease. In true
Free Fall, without any air resistance, the Normal Force = 0 and you are
floating. Atwood's Machine -- two masses connected by a single cable via a
simple pulley. They share a common acceleration,

NOTE: There is no class on Monday 25 May 2009! Back in session on Tuesday 26 May 2009.

Monday 5/25: Memorial Day (Observed) -- No classes.

Tuesday 5/26: Static & Kinetic Friction continued: Examples using our
125 kg crate sliding on the floor. If object is at rest, need to
"test" to see if an applied external force exceeds the maximum static
friction force ("breaks the static friction barrier"). Static
Friction can vary from zero to its max value in either direction. Finding the
coefficient of static friction by tilting µ_{s} =
tan(theta_{max}). Similar for kinetic friction, except one has to tap
the board to "break the static friction barrier". Rubber on concrete.
Can µ be greater than 1? Means theta_{max} greater than 45°
-- rare, but yes. We are not done with Forces, but some problems cannot easily
be solved by using forces. Collisions, for example, are very complex if we have
to put in all the forces of bending and breaking and mashing things. Need a
simpler way of looking at the problem. "Inertia" is a word which
isn't used much today, but it is the same as "momentum" -- represents
some kind of relentless quality of movement. It takes a force to change the
momentum, otherwise it just continues on, i.e., Newton's 1st Law. Linear
Momentum ( p = mv ) is a vector quantity. Newton's form of the 2nd Law -- F =
change in momentum / change in time instead of F=ma, but really the same thing.
Two extremes in collisions: Totally Elastic Collision (perfect rebound, no
damage) and Totally Inelastic Collision (stick together, take damage). Linear
momentum is conserved in all types of collisions . Totally Inelastic Collisions.
Example: The Yugo and the Cement Truck with numbers. Real Head-On collisions.
Second set of Sample Exam 2's handed out. (Click here and here
for a copy.) Q10 is a Take-Home quiz, handed out Tuesday 26 May 2009, and due
Thursday 28 May 2009. *NOTE: In part (b), you should know that there is a
range of forces F _{1} that combined with friction will keep the block
from moving. We want you to figure out the maximum friction force and use that
to figure out the maximum applied force F_{1} .*

Wednesday 5/27: No class.

Thursday 5/28: Hand back Q4-Q7. Looking again at crate on inclined plane
with friction. Depending on the ramp angle and an applied force up or down the
ramp, static fiction may point up or down the ramp -- or be zero. The maximum
angle that static friction can hold the crate at rest is theta_{max} =
tan^{-1}(µ_{s}). Totally Inelastic Collisions. Examples:
Head-on Collisions. Rear-end Collisions. (The Non-Collision -- if the car
following is going slower, it isn't going to run into the car ahead. PTPBIP.)
2-D Side Impact (vector) collision. Real crashes. More on airbags. Interactions
of safety systems. The myth of it being better to be "thrown clear from
the wreck". What happens in a wreck. How airbags work. Note: We do NOT
want our cars to have Totally Elastic Collisions -- the whiplash on our fragile
bodies would be awful. Instead, our cars are designed to crumple and
"die" for us. What's the opposite of a collision? An explosion. Or
recoil. Example: A pitcher on ice skates at rest -- when he hurls a fastball to
the right, he goes to the left. Total momentum of the system remains constant
(in this case, zero). Third set of Sample Exam 2's handed out. (Click
here for a copy.) Q11 Take-Home quiz, due
Monday 1 June 2009.

Friday 5/29: We've talked about How things move (Kinematic Equations) and Why things move (Forces, momentum). Now we want to talk about the Effort to make things move. Work: A Physics Definition (Work = Force times distance in the same direction). Work = Energy. Kinetic Energy -- an energy of motion, always positive, scalar, no direction information. Work-Energy Theorem (net Work = Change in K.E.). Using the Work-Energy Theorem to find a final speed. Potential Energy: Storing energy from applied work for later. Gravitational P.E. = mgh. Location of h=0 is arbitrary choice. Conservation Laws are very important in Physics. Conservation of Total Mechanical Energy (T.M.E. = K.E. + P.E.). Lose angle and directional information because energy is a scalar, not a vector. We can change height for speed and vice versa. Note: We do NOT want our cars to have Totally Elastic Collisions -- the whiplash on our fragile bodies would be awful. Instead, our cars are designed to crumple and "die" for us. Kinetic Energy -- an energy of motion, always positive, scalar, no direction information. Kinetic Energy is NOT conserved in an inelastic collision. Totally Elastic Collisions. Close approximations: The Executive Time Waster. Why you want inelastics collisions in a wreck. 5 mph versus 3 mph impact bumpers. "Adobe: The Little Car Made of Clay". Q12 Take-Home quiz, due Monday 1 June 2009.

REMINDER: Exam 2 is on Tuesday 2 June 2009.

Monday 6/1: Continue with Conservation of T.M.E. (P.E. + K.E.) on a roller
coaster. Total energy limits maximum height. If speed at top of the first hill
is about zero, then this P.E. is all we have. Cannot get higher, but we can
change height for speed. Newton's Universal Law of Gravity (or
Newton's Law of Universal Gravity). Takes two
masses -- there are two forces, according to Newton's Third Law. Use Universal
Gravity to check "g". The value we calculate is close, 9.83m/s²,
which turns out to be only off by 0.2%. Why is it off? Because using Univeral
Gravity in this manner makes the assumption that the entire Earth is uniform
and homogenous from the surface to the core -- which it is not. We would need
calculus to integrate over layers to get the observed value of 9.81m/s².
UCM Revisited. The Shuttle in Low Earth Orbit (Revisited). Centripetal Force,
F_{c} = m a_{c}. Something has to cause the centripetal force,
so it goes on the "ma" side of the sum of forces equation, because
centripetal force by itself doesn't appear on the F.B.D. No such thing as
Centrifugal Force. Only the Centrepital Force, which points radial inward, just
like the centripetal acceleration. You aren't forced to the outside, you merely
move in a straight line unless there is a force to keep you on the circle. Test
tube example. Using rotating cylinder to create "artificial gravity"
in space. The story of the 50,000 rpm Ultra-Centrifuge and the Fresh Rat's
Liver.

Tuesday 6/2: Exam 2.

Wednesday 6/3: No class.

Thursday 6/4: Return X2. Newton's Law of Universal Gravity (con't.) The difficulty in finding the universal constant G. How do you find the mass of the planet you're standing on? Tides (high/low, spring/neap). Power = Work / time. Power is rate that work can be done. 1 horsepower = 1 h.p. = the amount of work that one man, one horse and one plow can do in a day. An engine with "more power" can either do the same work in less time, or do more work. Three Classical States of Matter: Solid, Liquid, Gas. Combinations: Condensed Matter (covers both Solids and Liquids) and Fluids (covers both Liquids and Gasses). Two Extreme States of Matter: Plasma (electrons stripped off, high temperature), Cryogenics (extreme cold, odd behavior). Up until now, our objects really haven't had any dimensions. Extended Objects: Mass occupies a volume and shape. Mass-to-Volume Ratio (Density). NOTE: Do not confuse the Density of the Materials with the Mass-to-Volume Ratio of the OBJECT. Q13 Take-Home, due Monday 8 June 2009.

Friday 6/5: Density of Water built into the SI metric system (1 gram/cm³ = 1000 kg/m³). Floating on the Surface: Mass-to-Volume Ratio of the boat < Mass-to-Volume Ratio of the Liquid. Why Boats Float. Example: Front lab table as a 250 kg boat with 4.00 m³ volume. Buoyant Force = Weight of the Boat = Weight of the Water Displaced by the Submerged Part of the Boat. Calulating the amount of the boat submerged, by using the fact that the mass of the boat and the displaced water are the same. Water is unusual in that the mass-to-volume ratio of ice (solid) is LESS than liquid water, so ice floats. Ice which floats doesn't add to volume of water when it melts, but grounded ice (non-floating) does. This is one of the reasons why people worry about what global warming might do to the great ice sheets around the world. Sinking of the Edmund Fitzgerald and the RMS Titanic. Pressure = Force / Area. SI unit: Pascal (Pa). Example: Squeezing a thumbtack between thumb and forefinger. 1 Pa = 1 N/m², but Pascals are very small, so we get a lot of them. One Atmosphere standard air pressure = 1 atm. = 14.7 psi = 101,300 Pa. Topic 2 Worksheet 1 (Click here for a copy and directions.) Q14 Take-Home, due Tuesday 9 June 2009.

NOTE: Monday is the last day to turn in a Draft Paper if you want to. The only people required to do a draft are those who are reading an approved book not on the booklist.

NOTE: Thursday is the first day to turn in your final Topic 1 Science Literacy Book Report paper.

Monday 6/8: Pressure = Force / Area. SI unit: Pascal (Pa). Example: Squeezing a thumbtack between thumb and forefinger. 1 Pa = 1 N/m², but Pascals are very small, so we get a lot of them. One Atmosphere standard air pressure = 1 atm. = 14.7 psi = 101,300 Pa. Pressure at a depth due to supporting the column of liquid above. Absolute (total) Pressure vs. Gauge Pressure (difference between two readings). Pressure due to a column of water = 1 atm. at h = 10.33m = 33.86 feet. The perils of SCUBA diving. How to get liquid out of a cup using a straw -- or why Physics does not "suck", but pushes using a pressure difference. Using a column of liquid to make a barometer to measure air pressure. Switch from water to mercury changes h at 1 atm. from 10.33 m to 0.759m. The aneroid barometer. Smooth Fluid Flow. Pressure from a column of liquid looks like P.E. Create a Kinetic Pressure term which looks like K.E. to create Bernoulli's Equation and the Continuity Equation. Water Tower and the Faucet Problem. Bernoulli continued. The faster the fluid flow, the lower the Pressure. Example: The aspirator -- a vacuum pump with no moving parts. Example: Air flow around a wing. (Faster air over top means lower pressure on top, so net force is up -- Lift.) Why the Mackinac Bridge has grates on the inside north- and soundbound lanes.

Tuesday 6/9: Why the water tower needs a vent. Why the steel bands wrapped
around an old fashioned water tower or a farm silo are closer together at the
bottom than at the top. Temperature & Heat. Heat = Energy. Two objects in
thermal contact, exchange heat energy, Q. If net heat exchange is zero, the two
objects are at the same temperature. Temperature Scales:
°F, °C and K (Kelvins).
Linear Expansion: Most objects expand when
heated, shrink when cooled. Length Expansion. Example: One 39 ft. (12.0m) steel
rail expands 5.88 mm from winter to summer, but that's 0.75 meters for every
mile of railroad track. Bridge expansion joints. Why "Bridge Freezes
Before Roadway" signs. Expansion joints. I-57 in Chicago and the expanding
asphault. *Question: Does the material expand into a hole when heated, or
does the hole expand? (Think about what happens to the disk removed from the
hole -- does it expand or contract when heated?) *Volume Expansion of Solids and Liquids.
Coefficient of Volume Expansion usually given for liquids; for solids, beta = 3
× alpha. Ideal Gas Law (PV/T = constant or our form:
P_{1}V_{1}/T_{1} =
P_{2}V_{2}/T_{2}) -- must use Kelvins for temp and
absolute Pressures, because neither P or T can be zero or negative. Q15
Take-Home, due Thursday 11 June 2009.

JUST FOR FUN: In PHYS-1070 we talk about so many topics and Dr. Phil often talks about "systems" and how they interact -- so it's no surprise that this video on YouTube that I discovered a couple of years ago is "just plain fun" on so many levels: http://www.youtube.com/watch?v=lBvaHZIrt0o. Enjoy.

Wednesday 6/10: No class.

Thursday 6/11: Remember: L = L_{0} + delta-L and V = V_{0} +
delta-V. Heat Energy (Q) and Temperature Change
& Phase Change. Add/remove Heat Energy Q will raise/lower the
temperature of a material using the Specific Heat (J/kg·°C) for
objects of mass *m*, or the Heat Capacity (J/mole·K) for objects with
*n* moles of atoms or molecules. Add/remove Heat Energy Q will change its
phase between solid-liquid-gas using the Latent Heat of Fusion,
*L _{f}*, between solids and liquids, or the Latent Heat of
Vaporization

Friday 6/12: Waves: Single Pulse vs. Repeating Waves. The motion of the material vs. the apparent motion of the wave. For Repeating Waves, we have a Repeat Length (wavelength) and a Repeat Time (Period). Frequency = 1/Period. Wave speed = frequency x wavelength. Demonstration: the Slinky shows both longintudinal (string type) and transverse waves (sound type). Waves and Resonance continued. Standing Waves on a string. Fundamental, First Overtone, Second Overtone, etc. Demonstration: First and higher overtones on a string driven by a saber saw. (Can't see the Fundamental on the saber saw demo, because the tension required usually breaks the string.) Standing Waves in a tube. Tuning forks, resonance boxes. Musical instruments: Accoustic string instruments have a resonance box. Brass instruments start from the "natural trumpet", which can only play the fundamental and overtones for the pipe. Woodwind instruments get more complicated. The range of "normal" human hearing: 20Hz-20,000Hz (10 octaves). Tuning forks, resonance tubes. Acoustics of concert halls. Artilleryman's ear -- mid-range hearing loss. Video: The Tacoma-Narrows Bridge Disaster. Second day to turn in Topic 1 book reports. Second set of Sample Exam 3's (Click here and here for a copy.) Q17 Take-Home, due Monday 15 June 2009.

NOTE: Find out which ultrasonic ringtones you can hear!

REMEMBER: (1) Monday is the last day to turn in your Topic 1 Book Report, (2) Tuesday is Exam 3 so make sure your formula card is up to date, and (3) Don't forget about taking data for your Topic 2 Worksheets!

Monday 6/15: The Realization that Electricity and Magnetism were part of the
same Electromagnetic Force was a great triumph of 19th century physics. Greeks
knew about static electricity -- build up charge and get sparks. ~~Demo:
Static electricity~~. The Two-Fluid Model of Static Electricity (A &
B), to account for the two types of behavior noted. Franklin's One-Fluid Model
of Electricity. Occam's Razor: If you can't decide between two competing ideas
for how Nature works, take the simpler model. Real
Electric Charges. Two charges: like charges repel, unlike (opposite)
charges attract. Coulomb's Law looks like
Newton's Law of Universal Gravity. 1 Coulomb
of charge is an enormous amount of charge. Two 1.00 C charges separated by 1.00
meters have a force of one-billion Newtons acting on each other. Four
Fundamental Forces in Nature: Gravity, E & M, Weak Nuclear Force, Strong
Nuclear Force. The Hydrogen Atom. Gravity loses to
Electric Force by a factor of 200 million dectillion (!!!). Likewise,
the two protons in the nucleus of the Helium Atom
require the Strong Nuclear Force to overcome the 231 N electric repulsion.
Isotopes are the same element (proton number Z), but with different numbers of
neutrons (N). Some isotopes are stable, some are unstable and undergo
radioactive decay.

Tuesday 6/16: Exam 3. *Also...* Hand back more graded quizzes. First
set of Sample Final Exams. (Click here and
here for a copy.) Q18 Take-Home quiz, due
Thursday 18 June 2009.

Wednesday 6/17: No class.

Thursday 6/18: How does q_{1} know that q_{2} is there? --
"Action at a Distance" -- Gravity and the Electric Force are not
contact forces. The mathematical construct of the Electric Field. E is not an
observable quantity. (Side example: Methods of measuring speed v, do not
directly measure speed v.) Electric Fields, E = k q / r² (E-field from one
point charge) and F_{E} = q E (Electric Force = charge times E-field
the charge is emersed in). Maximum E-field in air, E-max. Electric Potential (Voltage).
Spark gaps. Voltage can be measured, then used
to find strength of E-field. SI units: E-field is (N/C) or (V/m) - both work.
Charges tend to accumulate on long pointy things, which explains why church
steeples get hit by lightning. Or why it's your fingertips which can get
shocked when reaching for the light switch after walking on carpet in the
wintertme. Conductors (metals) versus non-conductors (insulators).
Semi-Conductors sit in the middle. Sometimes they conduct and sometimes they
don't. This means they act like a switch or valve, and this is the basis for
the entire electronics semi-conductor industry. D.C. and A.C. circuits.
Ohm's Law. V=IR form. (Ohm's "3
Laws"). The Simplest Circuit: Battery, wires, load (resistor). Power
dissipated by Joule heating in a resistor. P = I V (3 forms of Power equation
to with Ohm's "3 Laws"). The Simplest Circuit: Battery, wires, load
(resistor). Series and Parallel Resistors.
Discussion of Significant
Figures again. Two devices connected together in a circuit can only be
connected two ways: series or parallel. In Series, same current, share voltage.
Equivalent resistance is always larger. In Parallel, same voltage, share
current. Equivalent resistance is always smaller. Story of radio
"repair" call from 4,000,000,000 miles. Q19 Take-Home quiz, due
__Friday 19 June 2009__.

Friday 6/19: Return X3. The Great 19th Century Debate: Is Light a Particle
or a Wave? (Wave-Particle Duality did not seem obvious at the time.) The
Electromagnetic Wave travels at the speed of light. c = 300,000,000 m/s =
186,000 miles/sec. Electromagnetic Spectrum: Visible light (ROYGBIV=red orange
yellow green blue indigo violet). Frequencies HIGHER and wavelengths SHORTER
than visible light (UV ultraviolet, X-rays, Gamma rays). Visible light is 400nm
to 750nm (4000 angstroms to 7500 angstroms). Cannot "see" atoms with
visable light, because the atom is about 1 angstrom across (1.00E-10 meters).
The visible light wave is too large to see something that small. So use X-rays.
Why Superman's X-ray vision cannot work -- because everyday situations are
"dark" in the X-ray band, thankfully! Frequences LOWER and
wavelengths LONGER than visible light (IR infrared, Microwave, Radio waves, ELF
extremely low frequency). Optics: Optics: Geometric Optics (empirical) and
Physical Optics (more wave and fieldlike). Ray Tracing: Rays from a spherical
source become essentially parallel rays when you are far away. When a straight
light ray hits a boundary between one material and another, three things can
happen: Reflection, Absorption, Transmission. The Law of Reflection. The Optical Lever -- move a
mirror by 10° and the reflected ray moves by 20°. (Dr. Phil's theory
on the origin of "seven years of bad luck for breaking a mirror".)
When light rays strike a rough surface, you get Scattering, which is
reflections off many different angles. People tend to not like photographs of
themselves, because they are used to seeing their mirror image -- their normal
image, which the rest of us sees, looks "wrong". The
Law of Refraction - Snell's Law. Light bent at
the interface between two media, because the speed of light changes in the
media. (Analogy: If you are driving along the road and your right tires go off
onto the soft shoulder, they can't go as fast and the car turns towards the
shoulder until all four wheels are driving off the road.) If going from an high
index of refraction media to a lower index media ONLY, have a chance for
Total Internal Reflection (T.I.R.). This is a
"perfect" reflection, better than a mirror. Used in high-end optical
systems instead of mirrors. Also useful in fiber optics cables. Thin Lenses.
Simplest lens surfaces are spherical (convex = bows out, concave = bows in) and
flat (plano). So some lenses might appear to be biconvex, plano-convex,
biconcave, convex-concave. A biconvex lens is also called a positive or
converging lens. Parallel light rays coming into such a lens will all pass
through the focal point, a distance *f* from the center of the lens. By
itself, could use as a magnifying lens. Concentrating sunlight: burning paper
or popping ants? Ray tracing gets same results as doing Snell's Law on mulitple
curved lens surfaces. Handy not to have to do all that refraction calculations!
Real image formed by passing three
rays through a positive thin lens. Three cases: object distance *p >
2f* (real, inverted, reduced image), *2f < p <
f* (real, inverted, magnified image), *p < f* (virtual, upright,
magnified image = magnifying glass) -- latter two not shown here. Second
set of Sample Final Exams -- the All-Titanic Exam. (Click
here for a copy.) Q20-21 is a Double
Take-Home quiz, due Monday 22 June 2009. *NOTE: Turn this in even if all you
have on it is your name, since it counts twice as two quizzes.*

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